Switch chamber for alternating currents



A. LATOUR SWITCH CHAMBER FOR ALTERNATING CURRENT Aug. 22, 1950 2 Sheets-Sheet l Filed Sept. 25, 1946 Aug. 22, 1950 A. LATOUR SWITCH CHAMBER FOR ALTERNATING CURRENT 2 Sheets-Sheet 2 Filed Sept. 25, 1946 Patented Aug. 22, 1950 OFFICE svvlrc'n CHAMBER ron ALTERNATING CURRENTS Andr Latour, Grenoble,4 France Appli-.cation September .25, 1946, Serial No. 699,185 In FlylliC- OCtOb 3, 1945 7 Claims". (Cl. 200--150) This invention relatesY to circuit interrupters of the oil blast type havingvpressure potsprovided with means ior regulating the discharge of arc extinguishing i'iuid across the arc.

An object of the invention is to provide interrupters in which the discharge of arc extinguishing' fluid across the arc is reduced to a minimum when the current itself is at a maximum' or in the vicinity of its maximum and increased to a maximum when the current value approximates zero.

Another object of this invention is tov provide interrupters in which the pressure pot is provided with pressure controlled discharge means, adapted to be opened in' order to prevent the blast of arc extinguishing fluid across the arc, whilst the current is at a maximum or the vicinity of the maximum, and to be closedv whilst the current approximates zero in order to cause the blast of arc extinguishing fluid.

Another object of this invention is to provide interrupters in which the pressurev pot is provided With blast passages, the opening of which or the eiiciencyl of which is prevented or reduced or delayed whilst the currentr is at a miximum and increasedv or accelerated when the current approximates zero.

According to an embodiment of my invention, I provide a pressure pot which is provided with' a chamber performing a to and fro movement in axial direction-that is the direction of the movement of the movable contact rodunder the pressure developed by the arc which remains in the pressure pot until it is extinguished.

Such movable chambers are known in combi# nation with interrupters of the type commonly called expansion interrupters, in which the chambers with their springs are constructed so as to let a strong pressure develop before a large discharge aperture is opened.

Accordingl to my present invention, such chambers are combined with blast interrupters and are constructed so as' to open immediately soas to' prevent or reduce any rise of pressure, whilst the current is at its maximum, and tor be closed when the current decreases to the vicinity of zero.

Simultaneously, the to andA fro movement of the chamber is utilized to prevent, delay or reduce the opening or the efficiency of the blast apertures of the pressure pot during the first part of the movement, and to accelerate the opening or increase the efficiency of the same during the second part of the movement.

Further features of thel invention will be more specifically pointed out inthe following disclosurein which reference is had to the accompanying drawing, both being given by Way of example and having no limiting character. Preferably but not necessarily, the disclosure and the drawing relate to devices in which pressure is provided by means of a partly or Wholly insulating liquid, but it is to be understood that within the scope of the invention said pressure may be obtained by means of an outside source of pressure gas or created by a solid substance which will be gasied by the action of the electric arc.

In the drawings:

Figure l is an axial sectional View of a switch according to the invention with transversal blowout;

Figure 2 shows the switch according te Fig. 1 at' the moment when the pressure generated by thearc reaches its maximum;

Figure 3 is an axial sectional view of a switch according to the invention with axial blow-out;

Figure 4 illustrates a switch laccording to the invention in which the arc is choked by the action of a jet of insulating fluid;

Figure 5 is an elevational View of a particular embodiment of the chamber fastening means, and

Figure 6 is a plan View of the arrangement shown in Fig. 5.

Referring now to Fig. l, the stationary contact l and the movable contact 2 are located in a chamberV 3 provided with a row of orifices situated one above the other. The relief orifice ii is located adjacent to the xed Contact l. In the position shown, where the pressure prevailing within chamber 3 is assumed to be low or nil, the orifice 5 is closed by a xed piston Il in which the contact l is accommodated. The blow-out orifices 5-8 are provided alongside the path of the movable contact 2 by which they will be covered or uncovered in the travel of the same. Tn the position of the movable Contact shown in Fig. l the orifices 8 and il are closed whilst the orifices 6 and 'l are uncovered. The chamber is held against its supporting base plate id by means of bolts' i l and i2' that carry nuts against which pressure springs i3' and i4 rest which here constitute the spring members. The whole assembly is secured to one end of a wall insulator it by means of a lead-in rod i6.

Fig. 2 shows the device after the pressure within chamber 3 has reached a snebst-anY va that is, as long as a considerable curi ont is nos ing through the arc. The pressure drives the chamber downwards relatively to the V" xed piston 4 while it stresses the springs i3' and H. This movement of the chamber uncovers the relief orifice whilst the movable contact closes the blow-out orifice ii partly and the blow-out orices l, 3 and 9 completely. Due to the fact that the displacement of the movable contact is designedly very slow as compared to that of the chamber, the movable contact will be substantially in the same position when the chamber, following the release in pressure, that is, as the current is nearing its zero value, is returned to its position shown in Fig. 1. It will be seen from this gure that the relief orice 5 is closed Whilst the blow-out orifices Si and formerly closed according to 2, are now uncovered, which means that maximum extinguishing action is exerted thereby upon the arc. Ii the blowingout effect turns out to be insucient, then the arc would be rehindled, with consequent increase in pressure and dashing of the chamber into the position shown in Fig. 2. Meanwhile, however, the movable Contact 2 has moved further away, and the blow-out orifices 3 and 9 will in turn be uncovered when the chamber is returned the next time due to the pressure being relieved as a consequence oi the current dropping almost to zero. This leads to the desired result that more blow-out orifices are uncovered when the current is substantially nil than when its Value is comparatively high. rihus, the extinguishing eiect is more powerful at minimum than at maximum current value. A further desirable result is obtained in that as long as a heavy current is flowing through the arc the gaseous products can easily through the relief oriiice. Thus pressure developed is limited, which enables the chamber to be made considerably lighter in weight. Finally, a lesser amount of power will be consumed by the arc burning at lower pressure, which is particularly advantageous from the viewpoint oi the stresses undergone by the switch.

Figure 3 illustrates an example of the application of this invention to a switch chamber with axial blow-out. The arrangement here is substantially the same as the one illustrated in Fig. l except that the blow-out orifices 6 and 'i are located coaxially with the movable contact. Underneath orice l' the interior of chamber 3 is enlarged Vso as to for-.i a circular chamber 3 which is connected a plurality of circumferentially arranged orifices 'i' to the outside. It will be seen that just as in the embodiment illustrated in Fig. 1 a rise in pressure will cause the chamber to move towards the movable contact, which results in the blow-out orices l and 5 being closed and the relief orifices 5 uncovered, whilst in the reverse movement which closely precedes the dropping of the current to zero the blow-out oriices l and 6 are uncovered and the relief orices 5 are closed again. The uncovering of orifice 'i is aided in its effect by the orices 'l' which are in connection with orice l through the circular chamber 3. When contact 2 moves downwards relatively to chamber 3 it uncovers rst the oriilce l at its upper edge and then establishes the connection of orice 'l with the circular chamber 3 when the movable contact 2 passes the lower edge of orice l which will put the orifices l into operation.

Figure 4 shows by way of example an application of the invention to a switch chamber in which the arc is blown out by a jet of liquid that rushes radially into a blow-out orifice. One single blow-out orifice 5 is provided here, forming the end of a bore il in the movable contact 2 which opens outside the chamber at its end remote from the blow-out orifice. The whole is immersed in a suitable liquid, for instance oil.

The operation of this device is as follows: When the arc strikes within the chamber it becomes surrounded with a gas bubble into which the end oi the movable contact 2 protrudes. The latter will protrude all the more as by the effect of the pressure set up by the gases chamber 3 moves towards said movable contact, most of the oil thus being carried with said chamber, which oil consequently is trapped in the bottom of the chamber from which it cannot escape through the orice 6 since the latter emerges from the liquid. Therefore, the hot gases are free to escape through the relief orifices 5 as well as through oriilce 6 which acts as an additional relief orice and is made ineffective from the viewpoint of its extinguishing action. As the pressure is relieved due to the current drop the chamber is returned quickly together with the oil whose level follows integrally the displacements of the chamber. In the course of such ascending motion the orifice 6 is suddenly flooded by the oil which is rushed thereinto by the residual pressure, whereby it actually chokes o the arc just at that moment when it still carries a low current. Definitive extinction is thus secured and any lrindling precluded. Grooves i8 of a greater or smaller depth and projections i9 located at a greater or shorter distance from the movable contact may be provided so that the oil can follow more readily the very swift movements oi the chamber.

The chamber can more easily be taken to pieces where the arrangement shown in Figs. 5 and 6 is used. With this end in view the spring members, e. g. coils springs i3, act on bolts ii which are formed with a neck portion 2l and a pair of shoulders 22, 23 shown at the left of Fig. 5 which is a fractional sectional view taken along line X--X of Fig. 6. When no pressure is prevailing in the chamber the shoulder 22 is held in engagement with the chamber by spring i3. Milled in the chamber-supporting plate are slots 2Q through which the shoulders can move Awhen a rotational movement is imparted to the chamber in the direction of the arrow F (Fig. 6). A latch 2d under the action of a spring 25 prevents any unintended loosening of the chamber from its supporting plate. When a pressure exists within the chamber the spring i3 is compressed by the amount necessary for such displacement; shoulder 22 disengages its seat but shoulder 23 still holds bolt H retained by plate li). In order to take away the chamber it is only necessary to push the latch 2,6 aside and to swivel the whole against the direction shown by the arrowl F.

I claim:

l. A circuit interruptor of the uid blast type comprising a pressure pot; a stationary and a movable contact in said pot; a chamber forming part of said pot and arranged for to and fro movements in axial direction; a discharge aperture in said chamber arranged for being opened and closed duringV the to and fro movement of said chamber whereby the increase of the pressure in said pot is diminished when the current is in vicinity oi its maximum; and blast apertures in the wall of said chamber located along the path of said movable contact whereby the blast discharge is diminished When the current is in vicinity of its maximum, and increased when the current approximates zero.

2. A circuit interruptor as claimed in claim 1,

contact.

3. A circuit interru said blast apertures n ly to the direction ci contact.

4. A circuit interruptor of iin' comprising a pressure pot; a sta hunan; conv and a hollow movable contact 1 chamber forming part of said pot for to and fro movements in axial Y discharge aperture in said chamber being opened and closed du n movement of said chamber the current is in vicinity of its blast aperture in said hollow nuovi4 5. A circuit interrupt-ei. of the t! ,1 comprising in combination, a pressure l f tionary Contact in said pot; a movable cont in contact with said stationary into .i A ond position spaced lrorn stationary contact and vice versa; a discharge aperture said pressure pot arranged so as to be automatically opened when the pressure in said pressure pct increases beyond a predetermined value; and at least one blast aperture in said pressure pot arranged so as to be in open position only when said disolaarge aperture is closed and said movable contact is in the second position spaced from said stationary contact.

6. A circuit interrupter oi the iiuid blast type, comprising in combination, a pressure pot; a stationary Contact in said pot; a movable contact in said pressure pot movable from a irst position in contact with said stationary contact into a second position spaced from said stationary contact, and vice versa; a discharge aperture in said pressure pot arranged so as to be automatically Opened when the pressure in said pressure pot increases beyond a predetermined value; and at one aperture in said pressure pct cocp erating with said movable contact and arranged so as to be in open position only when said discharge aperture is closed and said movable contact is in the second position spaced from said stationary contact.

7. A circuit interri'ipter or" the fluid blast type, cor` crising in combination, a pressure pot; a stationary cont-ast in said pot; a movable contact in said pressure pot movable freni a rst position in contact with said stationary contact into a second position spaced frein said stationary contact, and vice versa; a discharge aperture in said pressure pot arrarhed so as to be automatically opened when the nvssure in said pressure pot increases beyond a predeiv iined value; and at least one blast aperture in said pressure pot located along 'the path of said movable contact and arranged so as to be in open position only when said discharge aperture is closed and said movable contact is in the second position spaced from said stationary contact.

ANDRE' LATOUR.

The following references are of record in the or" this patent:

UIT-FED STATES PATENTS Nurnber Name Date 2,922,243. Kopeliowitsch NOV. 26, 1935 2,036,806 Ehrenberg et al Apr. 7, 1936 FUREIGN PATENTS Number Country Date 724,251 France Jan. 25, 1932 

